DNA blood tests can tell baby's sex at seven weeks

WASHINGTON: Tests that measure DNA in a pregnant woman's blood work well for telling the sex of a baby after seven weeks' gestation without posing danger to the foetus, a US study said on Tuesday. The meta-analysis of previous studies on the topic suggests that using cell-free fetal DNA from the mother's blood is more accurate than a urine test or sonogram and is safer than amniocentesis. It can also be done earlier than an ultrasound, which is usually accurate from 11 to 14 weeks, or amniocentesis, which samples fluid from the sac surrounding the foetus and carries a small risk of miscarriage. "The availability of a reliable non-invasive alternative to determine foetal sex would reduce unintended foetal losses and would presumably be welcomed by pregnant women carrying foetuses at risk for disorders," said the study in the Journal of the American Medical Association. The ...